Cigarette smoke attenuation of poly I:C-induced innate antiviral responses in human PBMC is mainly due to inhibition of IFN-beta production.
The cellular response to dsRNA or its synthetic analog polyinosinic-polycytidylic acid (poly I:C) results in IRF-3-, IRF-7- and NF-kB-mediated activation of type 1 IFNs and pro-inflammatory cytokines critical for innate antiviral immune responses. To investigate whether cigarette smoke compromises type 1 IFN signaling in humans, peripheral blood mononuclear cells (PBMCs) from non-smoking individuals were treated with smoke-conditioned media (SCM) and stimulated with poly I:C. We observed a marked attenuation of IRF-3 and NF-kB activation in PBMCs exposed to SCM compared to control PBMCs. Similarly, PBMCs from smokers or splenocytes from smoke-exposed mice also displayed marked reduction of poly I:C-induced antiviral responses compared with either non-smokers or sham-exposed mice. Cigarette smoke was found to block the production of type I IFNs following poly I:C treatment and inhibit subsequent STAT1 activation. Finally, we confirmed that inhibition of IFN-beta, but not IFN-alpha, predominantly contributes to the cigarette smoke-mediated suppression of innate antiviral responses. These findings provide novel mechanistic insights to the susceptibility of cigarette smokers to viral infections.
Mian
M Firoz
MF
Department of Pathology and Molecular Medicine, Centre for Gene Therapeutics, McMaster University, Hamilton, Ontario, Canada.
Stämpfli
Martin R
MR
Mossman
Karen L
KL
Ashkar
Ali A
AA
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects* / Q000235:genetics; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016899:Interferon-beta / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011070:Poly I-C / Q000494:pharmacology*; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014709:Vero Cells; D018116:Vesiculovirus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
D000998:Antiviral Agents; C494232:IRF3 protein, human; D050838:Interferon Regulatory Factor-3; C494233:Irf3 protein, mouse; D016328:NF-kappa B; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C494080:Stat1 protein, mouse; D016899:Interferon-beta; D011070:Poly I-C